From patchwork Wed Aug 19 10:33:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ani Sinha X-Patchwork-Id: 1347688 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=anisinha.ca Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=anisinha-ca.20150623.gappssmtp.com header.i=@anisinha-ca.20150623.gappssmtp.com header.a=rsa-sha256 header.s=20150623 header.b=EyRE9dj9; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4BWkfc1j5Sz9sPC for ; Wed, 19 Aug 2020 20:34:16 +1000 (AEST) Received: from localhost ([::1]:37840 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k8LQ6-0006Hy-1T for incoming@patchwork.ozlabs.org; Wed, 19 Aug 2020 06:34:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33740) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k8LPj-0006Hr-2r for qemu-devel@nongnu.org; Wed, 19 Aug 2020 06:33:51 -0400 Received: from mail-pl1-x62e.google.com ([2607:f8b0:4864:20::62e]:40120) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1k8LPg-0001X3-Qe for qemu-devel@nongnu.org; Wed, 19 Aug 2020 06:33:50 -0400 Received: by mail-pl1-x62e.google.com with SMTP id u10so10609573plr.7 for ; Wed, 19 Aug 2020 03:33:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=anisinha-ca.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id; bh=mVCHGGCNRthV6iKZdUGaurW9X8CgR/hSsXloHLcmHY8=; b=EyRE9dj9h/hhOuXn1az8uGGTvhdwc+OoXIZR/2e2ib7aGxzT681MhdFjEzuZs2Pcn4 98ICafCa9bsKORo5wtzQh+jhNXRkVj0QDTSHU5ZOVoAvz3sSRAFlof2PNNm4Y4g2RYPn o+sKd6dNcHzIy5NCRyxQHc5JWoo9IEaxmPwIxPcvNwQx3tXpdMQLrTcX8OfDHcuQUNs7 ppeFOcyxw7l7v+8YzkGVD4/JjgmBaTIxthxKFUdzi67+yls6zS0UEJu4obqbnCB9Lmcg 0KaroF37ixMI3/XKAAtSDuwXl11eoHO+14Dubew0atd0A0/4JDVNLCteh8pjoTYky4an gSpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=mVCHGGCNRthV6iKZdUGaurW9X8CgR/hSsXloHLcmHY8=; b=QzYNY4gBiLOseTP5vLan93oOy2MQYXVi5+bIQFR8cD6Dugt+LqzDwc8TrSwP+cZPKZ 5B02Yjo/wbvDZDVO/sebFFWgZEyzk7YzSH3CDlwj85ycLgj+/KO81CSeyqpFO1fpx/X/ yEPPAPMQwr0e7bHJGbs2kr52HvxDTwyjv2EPFFFoE6imzLOY9jmkuZG6d/wnr9BJLAGM l0AKM6Md5r/nYoJJDhlXfavzYLxZdfa0oIXpnPtnmzK7esK+KWitTwJkWliipM+zrbYG 4gsWT3kfVm8rnJD+Xy3Oz4q4C+1MzdUiRb5gG1uBuySeZgfnnA4LtQ1y+T0OydNs34/j rqOQ== X-Gm-Message-State: AOAM530dP/FkBvJMbhpOlYXjnszZicKpf64lwMWFoa0p76bnhfhv9mju yLrC3LesNNryt3Z9ki8t9HBkf3WkfKVQfAP9 X-Google-Smtp-Source: ABdhPJyhFgoP+5VBl/7upayVSyyCDa881r9tGu7XW81836QKDFAULD1riico2EF202vXYPJ0Dibxiw== X-Received: by 2002:a17:902:43:: with SMTP id 61mr19425522pla.16.1597833225885; Wed, 19 Aug 2020 03:33:45 -0700 (PDT) Received: from localhost.localdomain ([115.96.140.151]) by smtp.googlemail.com with ESMTPSA id i72sm21660722pgc.70.2020.08.19.03.33.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Aug 2020 03:33:44 -0700 (PDT) From: Ani Sinha To: qemu-devel@nongnu.org Subject: [PATCH V4] Introduce a new flag for i440fx to disable PCI hotplug on the root bus Date: Wed, 19 Aug 2020 16:03:28 +0530 Message-Id: <20200819103328.16788-1-ani@anisinha.ca> X-Mailer: git-send-email 2.17.1 Received-SPF: none client-ip=2607:f8b0:4864:20::62e; envelope-from=ani@anisinha.ca; helo=mail-pl1-x62e.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eduardo Habkost , "Michael S. Tsirkin" , Aleksandar Markovic , Paolo Bonzini , Ani Sinha , Igor Mammedov , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Aurelien Jarno , Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" We introduce a new global flag 'acpi-root-pci-hotplug' for i440fx with which we can turn on or off PCI device hotplug on the root bus. This flag can be used to prevent all PCI devices from getting hotplugged or unplugged from the root PCI bus. This feature is targetted mostly towards Windows VMs. It is useful in cases where some hypervisor admins want to deploy guest VMs in a way so that the users of the guest OSes are not able to hot-eject certain PCI devices from the Windows system tray. Laine has explained the use case here in detail: https://www.redhat.com/archives/libvir-list/2020-February/msg00110.html Julia has resolved this issue for PCIE buses with the following commit: 530a0963184e57e71a5b538 ("pcie_root_port: Add hotplug disabling option") This commit attempts to introduce similar behavior for PCI root buses used in i440fx machine types (although in this case, we do not have a per-slot capability to turn hotplug on or off). Usage: -global PIIX4_PM.acpi-root-pci-hotplug=off By default, this option is enabled which means that hotplug is turned on for the PCI root bus. The previously existing flag 'acpi-pci-hotplug-with-bridge-support' for PCI-PCI bridges remain as is and can be used along with this new flag to control PCI hotplug on PCI bridges. This change has been tested using a Windows 2012R2 server guest image on a Ubuntu 18.04 host using the latest master qemu from upstream. Signed-off-by: Ani Sinha --- hw/acpi/piix4.c | 8 ++++++-- hw/i386/acpi-build.c | 26 +++++++++++++++++++------- 2 files changed, 25 insertions(+), 9 deletions(-) Change Log: V3..V4: Added use case detail in the commit log as per Igor's suggestion. Also added an example of qemu commandline showing how to use the option. diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c index 26bac4f16c..4f436e5bf3 100644 --- a/hw/acpi/piix4.c +++ b/hw/acpi/piix4.c @@ -78,6 +78,7 @@ typedef struct PIIX4PMState { AcpiPciHpState acpi_pci_hotplug; bool use_acpi_hotplug_bridge; + bool use_acpi_root_pci_hotplug; uint8_t disable_s3; uint8_t disable_s4; @@ -595,8 +596,9 @@ static void piix4_acpi_system_hot_add_init(MemoryRegion *parent, "acpi-gpe0", GPE_LEN); memory_region_add_subregion(parent, GPE_BASE, &s->io_gpe); - acpi_pcihp_init(OBJECT(s), &s->acpi_pci_hotplug, bus, parent, - s->use_acpi_hotplug_bridge); + if (s->use_acpi_hotplug_bridge || s->use_acpi_root_pci_hotplug) + acpi_pcihp_init(OBJECT(s), &s->acpi_pci_hotplug, bus, parent, + s->use_acpi_hotplug_bridge); s->cpu_hotplug_legacy = true; object_property_add_bool(OBJECT(s), "cpu-hotplug-legacy", @@ -635,6 +637,8 @@ static Property piix4_pm_properties[] = { DEFINE_PROP_UINT8(ACPI_PM_PROP_S4_VAL, PIIX4PMState, s4_val, 2), DEFINE_PROP_BOOL("acpi-pci-hotplug-with-bridge-support", PIIX4PMState, use_acpi_hotplug_bridge, true), + DEFINE_PROP_BOOL("acpi-root-pci-hotplug", PIIX4PMState, + use_acpi_root_pci_hotplug, true), DEFINE_PROP_BOOL("memory-hotplug-support", PIIX4PMState, acpi_memory_hotplug.is_enabled, true), DEFINE_PROP_END_OF_LIST(), diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index b7bcbbbb2a..19a1702ad1 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -95,6 +95,7 @@ typedef struct AcpiPmInfo { bool s3_disabled; bool s4_disabled; bool pcihp_bridge_en; + bool pcihp_root_en; uint8_t s4_val; AcpiFadtData fadt; uint16_t cpu_hp_io_base; @@ -245,6 +246,9 @@ static void acpi_get_pm_info(MachineState *machine, AcpiPmInfo *pm) pm->pcihp_bridge_en = object_property_get_bool(obj, "acpi-pci-hotplug-with-bridge-support", NULL); + pm->pcihp_root_en = + object_property_get_bool(obj, "acpi-root-pci-hotplug", NULL); + } static void acpi_get_misc_info(AcpiMiscInfo *info) @@ -337,15 +341,18 @@ static void build_append_pcihp_notify_entry(Aml *method, int slot) } static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus, - bool pcihp_bridge_en) + bool pcihp_bridge_en, + bool pcihp_root_en) { Aml *dev, *notify_method = NULL, *method; QObject *bsel; PCIBus *sec; int i; + bool root_bus = pci_bus_is_root(bus); + bool root_pcihp_disabled = (root_bus && !pcihp_root_en); bsel = object_property_get_qobject(OBJECT(bus), ACPI_PCIHP_PROP_BSEL, NULL); - if (bsel) { + if (bsel && !root_pcihp_disabled) { uint64_t bsel_val = qnum_get_uint(qobject_to(QNum, bsel)); aml_append(parent_scope, aml_name_decl("BSEL", aml_int(bsel_val))); @@ -361,6 +368,9 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus, bool bridge_in_acpi; if (!pdev) { + /* skip if pci hotplug for the root bus is disabled */ + if (root_pcihp_disabled) + continue; if (bsel) { /* add hotplug slots for non present devices */ dev = aml_device("S%.02X", PCI_DEVFN(slot, 0)); aml_append(dev, aml_name_decl("_SUN", aml_int(slot))); @@ -419,7 +429,7 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus, method = aml_method("_S3D", 0, AML_NOTSERIALIZED); aml_append(method, aml_return(aml_int(s3d))); aml_append(dev, method); - } else if (hotplug_enabled_dev) { + } else if (hotplug_enabled_dev && !root_pcihp_disabled) { /* add _SUN/_EJ0 to make slot hotpluggable */ aml_append(dev, aml_name_decl("_SUN", aml_int(slot))); @@ -439,13 +449,14 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus, */ PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev)); - build_append_pci_bus_devices(dev, sec_bus, pcihp_bridge_en); + build_append_pci_bus_devices(dev, sec_bus, pcihp_bridge_en, + pcihp_root_en); } /* slot descriptor has been composed, add it into parent context */ aml_append(parent_scope, dev); } - if (bsel) { + if (bsel && !root_pcihp_disabled) { aml_append(parent_scope, notify_method); } @@ -455,7 +466,7 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus, method = aml_method("PCNT", 0, AML_NOTSERIALIZED); /* If bus supports hotplug select it and notify about local events */ - if (bsel) { + if (bsel && !root_pcihp_disabled) { uint64_t bsel_val = qnum_get_uint(qobject_to(QNum, bsel)); aml_append(method, aml_store(aml_int(bsel_val), aml_name("BNUM"))); @@ -1818,7 +1829,8 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, if (bus) { Aml *scope = aml_scope("PCI0"); /* Scan all PCI buses. Generate tables to support hotplug. */ - build_append_pci_bus_devices(scope, bus, pm->pcihp_bridge_en); + build_append_pci_bus_devices(scope, bus, pm->pcihp_bridge_en, + pm->pcihp_root_en); if (TPM_IS_TIS_ISA(tpm)) { if (misc->tpm_version == TPM_VERSION_2_0) {